The invention relates to plastic dispensing closures or like products with flaps for opening and closing a dispensing aperture.
Dispensing closures for bottles, cans and other containers frequently have one or more flaps that can be pivoted between open and closed positions to conveniently dispense product from the container without removing the closure. Examples of the general type of closures under consideration here are disclosed in the following United States Patents, the disclosures of which are incorporated herein by reference: U.S. Pat. Nos. 4,693,399, 4,936,494 and 5,330,082.
Where a flap or flaps are joined to the main body of the closure with an integral hinge, the closure is ordinarily molded of relatively resilient material. The resilient nature of the cap material causes the flap to exhibit a tendency when it is opened and released to spring back or relax towards the closed position. This tendency can be troublesome when the flap assumes a free position which obstructs a dispensing hole or holes in the closure. Numerous techniques have been proposed and used to hold the flap in an open position. Typically, these techniques involve a snap acting or over-center hinge or snap engaging elements apart from the hinge. A specialized hinge can be difficult to mold and can require large areas and/or a location which limits the geometry of the flap on the closure. Frequently, the snap engaging designs require that the closure be formed of two separate parts or have other expensive and/or complex geometries.
The invention provides a dispensing closure or similar product having a hinged flap with a mechanism to releasably hold the flap open. The disclosed stay-open feature is relatively easy to mold without complex tooling and offers flexibility to the designer in the selection of a stay-open position and can readily be applied to multiple flap closures. Moreover, the stay-open mechanism of the invention is readily adapted to one piece closures.
As disclosed, the invention provides a releasable snap lock mechanism that employs separate formations on the body of the closure and on the flap. The snap lock formation or component on the flap is spaced from the hinge joining the flap to the closure body so that it orbits or pivots around the hinge. The snap lock formation or component on the body lies in the path or orbit of the lock formation on the flap. The body lock formation is located relative to the path of the flap lock formation to determine the position at which the flap is held open and the level of retaining force available to maintain it open.